A journalist at the University of Missouri was challenged and physically blocked from filming protests at the school. The man was met with chants saying, "Hey hey, ho ho, reporters have got to go!" (YouTube/Mark Schierbecker)

In the 1960s, there were three broadcast television networks: CBS, ABC and NBC. That slowly grew, adding PBS and Fox, and then grew more rapidly with the advent of cable. Your television probably has several hundred channels to choose from -- but if you're of a certain age, you might not have a television. Instead, you might rely on the Internet, where there are a countless number of stations and a countless number of broadcast cameras. You have one in your pocket right now.

The shift that has taken place on television -- and in the print media and in radio -- is like the difference between a music festival before and after they stop checking tickets. It's no longer the case that ABC, CBS and NBC get to decide which things become part of their nightly newscasts, decisions necessarily limited by how much time there is in the day. Instead, anyone with a story to tell can tell it: Witnesses to accidents, witnesses to history, witnesses to this funny thing their cat did.

We've gotten used to that situation enough that a switch has happened. Now, we realize that being empowered to tell our own story means we don't necessarily need those three networks (or any of those newspapers or radio stations) to tell our stories for us. We can tell the story we want, without passing through anyone else's gate -- and, importantly, without anyone else sanding down the edges or adding other context.

A not-insignificant part of the Republican presidential candidates' lashing out at the media of late is predicated on that idea. Ted Cruz's campaign (and Hillary Clinton's campaign, for that matter) would much rather have you follow them on Twitter and Facebook, where you can get updates about what they're doing and about their policy proposals without your having to have those updates and proposals filtered by The Washington Post or CNN. When The Post and the news networks were the only way to reach a massive audience, candidates didn't have a choice. Now, to some extent, they do.

We've gotten sufficiently used to hearing directly from first-person sources that we now see more instances in which the first-person narrative differs from the story told by the media. Fans of candidates or followers of movements can see the addition of context or analysis as reflecting bias, rather than objectivity. (Instances in which the additional context or analysis might be unfair only heightens that suspicion.)

The confrontation between members of the media and students (and faculty) at the University of Missouri on Monday follows this same theme. When reporters tried to document a student encampment in the wake of the resignation of the school's president, Tim Wolfe, they were physically blocked from doing so. The group that led the protests that ousted Wolfe, Concerned Student 1950, determined that the encampment was a "safe space" in which students could "converse and build from fellowshipping," as it said in a tweet. "That isn't for your story."

There has been a great deal of conversation over the last 12 hours about whether or not the students and faculty were right in blocking access to the site. There has also been discussion of how and why members of the black community, in particular, might be distrustful of the role of media. (See this series of tweets from The Post's Wesley Lowery.) But part of the discussion, too, has been about the contrast between the media's coverage -- the "your story," above -- and the story seen through the eyes of the protesters.

If journalists simply told the story and Activists didn't want the truth told? That'd be different. Folks are just protecting themselves.

Social media has given a new voice to both the powerless and the powerful, each of whom has a story to tell and each of whom would rather tell it in their own way. The role of the media is to tell the stories of others as fully as possible, a role which necessarily shifts how the story is told. The tension between those two stories is not new; the subjects of media coverage have always complained about the end results. What's new is that, in many instances, there actually is no need for the media to be the conduit between the source and the reader.

Which pleases Ted Cruz and Barack Obama as much as it does a protester at the University of Missouri.